1. Field of the Invention
The present invention relates in general to covering open-topped vehicles, and in particular to covering open-topped freight vehicles. Specifically, the present invention relates to covering open-topped freight vehicles in a secure, yet efficient manner.
2. Description of the Prior Art
In recent years, it has become desirable to ship materials such as grain, granular materials, and the like that are subject to degradation or spoilage if exposed to the weather. Even many scrap and metal products should not be exposed to weather during shipping. Some products, such as sand or the like, while not subject to damage from the weather are still best not exposed during shipping due to the possibility that such materials may fly off of the freight vehicle and become a nuisance. Crushed-rock ballast is commonly stored and transported by railroads in ballast cars with open tops and bottom dispensing hoppers. Ballast is used year-round for track bed repair, but in icing conditions the ballast can freeze into a solid, unusable mass.
Since, for many reasons, it is easy to ship materials, such as mentioned above, in open-topped freight vehicles, such vehicles have received wide acceptance. However, due to the just-mentioned problems, as well as other requirements, such vehicles should be covered during the transportation of the material, and possibly also covered while the material is being stored in the vehicle if such storage is performed. Present open-topped freight vehicles come in many designs, and one example of such vehicles is the so-called gondola car. A gondola car is a flat-bottomed railroad car which has no top, fixed sides and often has removable ends, and is used to ship steel, rocks or heavy bulk commodities. Other examples of such open-topped vehicles include ballast cars, hopper cars and flat cars. Of course, other examples of such vehicles will occur to those skilled in the art based on the disclosure herein. Due to the possible variations in such vehicles, the dimensions of the vehicles can be subject to wide variations. In fact, vehicles of the same type, such as the just-mentioned gondola car, may have dimensions that vary among the vehicles of that same type. Thus, not all gondola cars have the same axial length, and so forth.
With regard to covering such vehicles, it is noted that many requirements exist. For example, the cover must be strong enough and mounted securely enough to resist coming off of the vehicle when subject to a strong wind as may occur during transit at high speeds, or as may occur if the vehicle encounters a strong wind storm. Such wind may find its way beneath the cover and thus lift it from the vehicle. Such strong wind may also tend to rip the cover and thus exacerbate the just-mentioned problem by establishing further paths for the wind to get beneath the cover.
However, these mounting and strength requirements are not easily satisfied as the cover must be mounted in place in an efficient manner, often in extremely harsh weather conditions. Thus, a cover that is made strong merely by having a great deal of material may not satisfy the total requirements as it may be expensive and also may be difficult to mount. Still further, a cover that is securely mounted may not satisfy the requirements of being efficient to mount in difficult weather conditions.
Basically, there are two choices when it comes to covering such open-topped vehicles: (1) a permanently attached cover; and (2) a temporary cover, or cover that is basically designed to be a single-use cover. Each of these choices has its advantages and each has its own particular drawbacks.
For example, while a permanent cover has the advantage of being adapted to be "customized" for a particular vehicle, it has a drawback associated with being expensive due to "loss" of the cover. "Loss" can occur due to handling or due to general degradation as a result of exposure to harsh weather conditions. If a vehicle having a permanent cover thereon is stored after use in a manner that does not lend itself to further use of the vehicle to carry the material for which the cover is most effective, the covered vehicle might be considered as being "lost".
Accordingly, some of the advantages of the permanently covered vehicle, especially the economic advantages, which are gained by making multiple uses of a single piece of equipment are vitiated if not entirely lost due to the "loss" of the cover. In any case, if the cover is made strong and secure but must be expensive to build or to use in order to accomplish this result, it is not a totally successful design.
On the other hand, a single-use cover can overcome some of the above-mentioned drawbacks of the permanent cover. For example, such a single-use cover is not as subject to degradation due to weather, is not as subject to expense due to a lack of multiple uses, and is not as likely to have a design requirement for multiple and varied uses as is the permanently attached cover. Accordingly, some of the problems associated with permanent covers are overcome by the single-use cover. By its basic nature, a single-use cover is not subject to the above-mentioned drawbacks associated with "loss" of the cover.
However, in overcoming some problems, the single-use cover presents problems of its own.
For example, since a single-use cover is designed to be assembled each time it is used, therefore, any difficulties in assembly are magnified many times over those same difficulties associated with a permanently attached cover. Thus, time and ease of assembly become important considerations in single-use covers.
Still further, a single use cover is best sold as a kit to be stored and assembled as necessary. Thus, to be most effective, the single-use cover should be "universally adaptable". That is, the cover furnished in a single kit should be amenable for use on a variety of vehicle dimensions. If a single-use cover cannot be designed to be "universally" adaptable, many different single-use covers may be required to fit all of the different types of vehicles and even the different sized vehicles of the same type. A requirement for many different single-use cover kits may vitiate or even defeat many of the economic advantages of such a device as compared to a permanently mounted cover.
A permanently mounted cover can have the advantage of being designed especially for the vehicle upon which it is used to be securely mounted thereon and to be as strong as possible for that particular vehicle; whereas, a single-use cover sold in a kit may not be perfectly adapted to the particular vehicle being covered and some security in mounting and strength of the cover may be lost. Thus, again, universal use requires sacrificing some advantages associated with customizing of the cover to the particular vehicle.
Yet another drawback associated with single-use covers as compared to the permanently attached covers may be that of consistent results. That is, when a cover is permanently attached to a vehicle, yet has some limitations, the user of that vehicle is able to learn what those limitations are and can account for them in his planning. However, a single-use cover cannot generate such a history, so each cover may have its own particular quirks and problems which a user may not be able to account for in a preoccurrence manner.
Accordingly, there is a need for a single-use cover that can be quickly, yet securely mounted on a vehicle even under difficult weather conditions, yet is adaptable to a wide variety of vehicles and can be designed to be consistent and strong, and thereby realize many of the advantages of both a single-use cover as well as a permanently attached cover without being subject to all of the drawbacks associated with each of such cover designs.